1. Field of the Invention
The present invention rates to poke-through connector and, more particularly, to a poke-through connector that may be assembled within an aperture in a concrete floor from one side thereof without the need for assembly from the other side. The poke-through connector assembly provides a fire-rated insulation between each side of the floor once assembled.
2. Description of the Prior Art
Modern high-rise buildings, such as office buildings, apartment complexes, condominiums and other structures, are typically built from a skeletal steel structure wherein the steel beams forming the structure are interconnected by rivets, bolts or other fasteners. The steel beams that form the floors of the structure are typically covered with corrugated steel plates upon which concrete may be poured or reinforced concrete may be poured without the use of the plates. The poured floors provide a resistance to the spread of heat that could ignite materials on an upper floor from a fire on the floor below.
One problem with maintaining the fire-rating of the poured concrete floors is the need to establish electrical wiring between them. This may be done by boring an aperture through the concrete floor and inserting a floor receptacle. Some receptacles used for this purpose have ignored the need for a fire-rated capability. See, for example, U.S. Pat. No. 3,646,244. Other connectors recognizing the need for closing the passageway formed by an aperture within a concrete floor have suggested the use of intumescent materials. See U.S. Pat. No. 3,864,883. The intumescent material used is a mixture of an intumescing binder and a filler which, when exposed to heat, expands rapidly. Such intumescent material may consist of sodium silicate or potassium silicate in combination with sodium bicarbonate, as suggested in U.S. Pat. No. 2,279,791, or in combination with clay or cellulatable glass as suggested in U.S. Pat. No. 3,864,883.
The use of intumescent material in electrical connector assemblies which are inserted into apertures within concrete floors has become a general standard as seen in U.S. Pat. Nos. 3,995,102; 4,099,020; 4,264,779; 4,336,416 and 4,477,694. However, these connectors suffer from configurations that permit the conduction of heat from one surface of the concrete floor to the other through metal-to-metal connections. All of the patents mentioned in this paragraph may be faulted because of this limitation. Typically, the metal-to-metal connections occur between upper and lower housings connected by screws and separated by intumescent rings sandwiched therebetween. The screws serve to conduct heat from the lower to upper housings. These prior art patents also thought that it is desirable to separate the wiring conduit into two compartments for electrical power wiring and signal wiring. This separation is established by a metal partition which extends from the lower housing to the upper housing through the aperture within the concrete floor. Examples of such partitions may be found in U.S. Pat. Nos. 3,995,102 and 4,477,694.
Many of the prior art connectors designed for use through concrete floors need to be assembled from both sides of the floor. In some designs, the housing on each side of the floor is larger than the aperture therethrough, see U.S. Pat. No. 3,995,102. In other designs, a special mounting bracket is required on the side of the connector opposite the electrical receptacle which requires an assembly operation on each side of the floor, see U.S. Pat. Nos. 4,091,231 or 4,336,416.